The present invention deals with a quick-disconnect coupling and valve assembly which is especially useful, but not limited to, the dispensing of liquids and semi-liquids from a collapsible bag of a bag-in-box package by various beverage syrup dispensing systems.
Various systems are in use or have been proposed for dispensing beverage syrup from a disposable package consisting of a flexible collapsible bag in a corrugated box commonly referred to as a bag-in-box dispensing package. One such system capable of use with the bag-in-box is illustrated in U.S. Pat. No. 4,014,461. The bag is provided with a fitment in the form of a spout through which filling and dispensing occurs and it is desirable to provide a quick-disconnect coupling between the spout and the service line of the pump or other type of beverage mixing and dispensing system. One such coupling is carried on the spout fitment of the bag and works in conjunction with the service line connector, and is commonly called in the art a single-service valve and coupling since it is discarded with the bag when it is emptied. This valve opens automatically as the line connector is connected to the spout and closes as it is disconnected therefrom to prevent syrup from drawing from the bag. Such a single-service valve is illustrated in U.S. Pat. No. 4,286,636, which shows it in combination with a dip tube. However, it is of such a nature, including a coil or equivalent spring arrangement for closing the valve, that it is expensive to produce and after use for a period of time, has a tendency to weaken and to become clogged with the sticky syrup and, therefore, does not always automatically close to prevent drainage from the bag.